Several pharmaceutical drugs are preferably or exclusively delivered by infusion or injection, traditionally by a hand-operated syringe equipped with a hypodermic needle. Though effective, this method is a source of discomfort for patients requiring repeated injections over an extended period, for example diabetes patients. Moreover a number of patients, in particularly elderly, visual-impaired, or patients suffering from arthritis, do not have the manual dexterity required to self-administer a hypodermic injection.
In some cases like dental injections in the gums, the injections discomfort and pain can be attenuated if the drug is delivered at a constant and moderate rate. Unfortunately this is not always possible, even with the best injection technique.
It is also known to employ special syringes, also termed “insulin pens”, adapted to deliver a precisely metered dose of drug through a fine-gauge needle, by the action of a piston operated by a press button. These pens are easier to use than conventional syringes, yet they still require a certain amount of dexterity and force, and some patients find their use difficult.
It is also known to use motorized infusion pumps when there is a indication to deliver a drug at a constant low rate protracted along an extended period.
US 2009105650 describes a drug delivery pump drive which uses a linear piezoelectric motor to advance a syringe piston to deliver a liquid drug. The pump drive, provided in a drug delivery pump, provides silent operation and very low energy consumption compared to electric motor-based drives.
US 2009097995 describes a syringe pump which uses the linear actuator applying a linear motion of a piezoelectric linear motor in moving the piston, such that suction and exhaustion of the fluid can be performed more precisely through controlling of power supply with respect to the piezoelectric linear motor. The syringe pump includes a cylinder which includes a receiving space, a piston which is mounted in the cylinder to pump liquid or powder in and out of the cylinder, and a piezoelectric linear actuator which moves the piston in a reciprocating manner. In addition, the piezoelectric linear actuator comprises a piezoelectric linear motor.
WO 03103763 describes a device for delivering fluid, such as insulin, to a patient. The device includes an exit port assembly, a syringe-like reservoir including a side wall extending along a longitudinal axis towards an outlet connected to the exit port assembly, and a plunger assembly received in the reservoir. Successively actuating the actuator causes longitudinal movement of the plunger assembly towards the outlet of the reservoir in order to dispense the fluid. According to one exemplary embodiment, the actuator comprises an elongated shape memory element. In a further embodiment, the actuator comprises a solenoid assembly.
US2007129681 describes a fluid dispenser having a housing for defining a fluid chamber. The housing has an orifice through which fluid is discharged. A piston is positioned in the housing for linear motion in the chamber for expelling fluid from the chamber and through the orifice. A piezoelectric actuator assembly is positioned in the housing for imparting the linear motion to the piston. In one example implementation, the fluid dispenser housing takes the form of a syringe. In the syringe implementation, a syringe housing defines an essentially cylindrical fluid chamber. In an example embodiment, the piezoelectric actuator assembly comprises a first piezoelectric actuator; a second piezoelectric actuator; and, a circuit for actuating the first piezoelectric actuator and the second piezoelectric actuator.
WO2008/003625 discloses an automatic infusion or injection device in which the amount and type of the drug contained in a cartridge is determined inductively.
All these embodiments involve complex electrical connections in order to provide power to the fluid delivery actuator. Moreover, feedback about the proper operation of the system, about status, etc, is not provided. Single part products comprising the fluid reservoir and the actuation means a higher costs product.